This area of Lakeport, California was flooded due to extreme weather during the 1998 El Niño event. El Niño causes changes in rainfall patterns around the world.
Click on image for full size
Courtesy of FEMA
El Niño and Other Climate Events
Sometimes the way the air moves around in the atmosphere changes.The way water moves through the ocean can change too. These changes can cause unusual weather for a few weeks or a few months or a year or more. Weather returns to normal when the atmosphere and ocean return to normal.
There are several different events that happen in the atmosphere and oceans. The largest are described below. These events are natural. However they might be changing because of global warming.
The El Niño-Southern Oscillation (ENSO) is the strongest of these events. It is caused by a change in the way air and ocean water moves in the tropical Pacific region. Both phases of ENSO – El Niño and La Niña – can cause changes in weather including intense rainstorms, drought, and a change in the amount of storms.
Changes in the North Atlantic Oscillation (NAO) affect winter weather in the Northern Hemisphere. The amount of snow and cold temperatures are affected by the NAO. The NAO is affected by other changes in the atmosphere like ENSO.
Last modified September 4, 2008 by Lisa Gardiner.
Shop Windows to the Universe Science Store!Cool It!
is the new card game from the Union of Concerned Scientists that teaches kids about the choices we have when it comes to climate change—and how policy and technology decisions made today will matter. Cool It! is available in our online store
You might also be interested in:
In some years there are many hurricanes. Other years there are only a few. Each year, scientists make predictions about what they think the hurricane season will be like. They can’t say for sure how many...more
Looking for online content that can be used for a climate change education course or module? Pages linked below can be used to support an introductory climate change education for either a unit or a full...more
Leaders from the countries of the world are heading to Copenhagen, Denmark in December 2009 to decide how the world will deal with climate change. They will make decisions about how to send less greenhouse...more
How do you know to pack your bathing suit and sunhat for a trip to a tropical island or pack warm sweaters and coats for a trip to Alaska? If you know a little about regional climates, then you know what...more
Only a tiny amount of the gases in Earth’s atmosphere are greenhouse gases. But they have a huge effect on climate. There are several different types of greenhouse gases, but they all have something in...more
Some satellites study Earth from space. Some of them study our atmosphere and weather. Some take pictures of clouds. Others use special instruments to make measurements of temperature, humidity, or the...more
To figure out what the Earth might be like in the future, scientists need to know how Earth reacts to changes. Models help scientists to better understand how the Earth works and how it will react to climate...more